Fix build errors on thumbv7a-*-windows-msvc targets

Resolves: #572

Author: kleisauke

src/backtrace/dbghelp.rs

@@ -167,11 +167,21 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
         Some(StackWalkEx) => {
             let mut stack_frame_ex: STACKFRAME_EX = mem::zeroed();
             stack_frame_ex.StackFrameSize = mem::size_of::<STACKFRAME_EX>() as DWORD;
-            stack_frame_ex.AddrPC.Offset = context.0.Eip as u64;
+
+            cfg_if::cfg_if! {
+                if #[cfg(target_arch = "x86")] {
+                        stack_frame_ex.AddrPC.Offset = context.0.Eip as u64;
+                        stack_frame_ex.AddrStack.Offset = context.0.Esp as u64;
+                        stack_frame_ex.AddrFrame.Offset = context.0.Ebp as u64;
+                } else {
+                        stack_frame_ex.AddrPC.Offset = context.0.Pc as u64;
+                        stack_frame_ex.AddrStack.Offset = context.0.Sp as u64;
+                        stack_frame_ex.AddrFrame.Offset = context.0.R11 as u64;
+                }
+            }
+
             stack_frame_ex.AddrPC.Mode = AddrModeFlat;
-            stack_frame_ex.AddrStack.Offset = context.0.Esp as u64;
             stack_frame_ex.AddrStack.Mode = AddrModeFlat;
-            stack_frame_ex.AddrFrame.Offset = context.0.Ebp as u64;
             stack_frame_ex.AddrFrame.Mode = AddrModeFlat;
 
             while StackWalkEx(
@@ -205,11 +215,21 @@ pub unsafe fn trace(cb: &mut dyn FnMut(&super::Frame) -> bool) {
         }
         None => {
             let mut stack_frame64: STACKFRAME64 = mem::zeroed();
-            stack_frame64.AddrPC.Offset = context.0.Eip as u64;
+
+            cfg_if::cfg_if! {
+                if #[cfg(target_arch = "x86")] {
+                        stack_frame64.AddrPC.Offset = context.0.Eip as u64;
+                        stack_frame64.AddrStack.Offset = context.0.Esp as u64;
+                        stack_frame64.AddrFrame.Offset = context.0.Ebp as u64;
+                } else {
+                        stack_frame64.AddrPC.Offset = context.0.Pc as u64;
+                        stack_frame64.AddrStack.Offset = context.0.Sp as u64;
+                        stack_frame64.AddrFrame.Offset = context.0.R11 as u64;
+                }
+            }
+
             stack_frame64.AddrPC.Mode = AddrModeFlat;
-            stack_frame64.AddrStack.Offset = context.0.Esp as u64;
             stack_frame64.AddrStack.Mode = AddrModeFlat;
-            stack_frame64.AddrFrame.Offset = context.0.Ebp as u64;
             stack_frame64.AddrFrame.Mode = AddrModeFlat;
 
             while dbghelp.StackWalk64()(

src/lib.rs

@@ -194,7 +194,7 @@ mod lock {
 
 #[cfg(all(
     windows,
-    any(target_env = "msvc", all(target_env = "gnu", target_arch = "x86")),
+    any(target_env = "msvc", all(target_env = "gnu", any(target_arch = "x86", target_arch = "arm"))),
     not(target_vendor = "uwp")
 ))]
 mod dbghelp;